Wireless communication refers to communicating voice, data, or any other information over a wireless medium such as air. Unlike wired mediums which are available only to transmitters/receivers that are physically connected to the medium, a wireless medium is inherently open and shared. Therefore, certain frequency bands (also referred to as bands, frequencies, frequency channels, or channels) of a wireless medium may be dedicated to certain users in order to guarantee communication quality and bandwidth availability. The demand for wireless spectrum has been continuously increasing with the increase in the number of wireless users (e.g., commercial cellular operators). One way to address this demand is to open the bands that have been previously dedicated to certain users. An example is the 3550-3700 MHz band (the 3.5 GHz band) which was previously reserved for military use but has been opened by the U.S. Federal Communications Commission (“FCC”) for shared use. Similarly, the 1695-1710 MHz, 175-51780 MHz, and 2155-2180 MHz bands (the “AWS-3” bands) have also been considered for shared use whenever federal incumbent systems relocate out of them.
When sharing spectrum, the users of the shared spectrum (e.g., federal and non-federal incumbent systems, access points of commercial cellular operators, etc.) should not interfere with one another, and in case of a usage conflict, higher priority users should be guaranteed access to the shared spectrum. In the 3.5 GHz band, the FCC has defined a three-tiered model of users, where incumbent users (e.g., federal and non-federal incumbent systems) are positioned at the top tier and have the highest priority, while public users (e.g., commercial cellular operators, emergency vehicles, police, etc.) are positioned at either a middle tier or a bottom tier. Specifically, some public users may obtain higher priority under a Priority Access License (“PAL”) and be positioned in the middle tier and have medium priority, while other public users may operate without a license under General Authorized Access (“GAA”) and be positioned in the bottom tier and have the lowest priority. Each PAL and GAA public use device may implement a communication system that operates according to a wireless communication technology or standard protocol (e.g., Long Term Evolution (“LTE”), Wideband Code Division Multiple Access (“WCDMA”), Global System for Mobile Communications (“GSM”), etc.) to communicate with one or more end user devices (e.g., smartphones).
One or more Spectrum Access Systems (“SASs”) may facilitate spectrum sharing among the incumbent and public users. The SASs monitor interference and dynamically assign frequency bands to various devices that consume shared spectrum resources such that devices with a lower priority do not interfere with those with a higher priority.